Zucchini should be shredded not mashed. Finely chop onion also.
Grease 9 x13 pan and pour into it. Mix finely shredded onion and zucchini with other ingredients. Pour mixed ingredients into pan and cover with aluminum foil. Bake at 350 degrees for 30-35 minutes. Let cool then cut into squares making it three rows by four rows. Can be frozen.